The cargo space of the conventional pickup truck is open and, therefore, unprotected from the weather. This can be a serious problem in the case of various types of cargo. This problem has been addressed in a number of ways in the past. One solution has been to provide a flexible cover of watertight material such as canvas which has been treated with a moisture sealing material or a plastic. Means are provided on the sides of the cargo space to tie down the cover. In this arrangement, access to the cargo space is attained by detachment and removal of the flexible cover.
Another solution has been to provide a rigid roof structure which is placed over the cargo bay and bolted, clamped or otherwise rigidly secured to the cargo bay. This type of structure normally has a rear door which is positioned above and cooperates with the tailgate of the cargo space. Access to the cargo area of the truck bed is exclusively through the rear opening provided by pivoting the rear door and tailgate panel to open position.
A still further solution has been a flexible cover supported on rigid cross pieces which are mounted on rails secured t the sides of the cargo space for fore and aft movement. This latter type of cover can be folded forwardly against the rear wall of the vehicle cab to expose the cargo bay.
Each of these solutions has a number of variations incorporating the basic structural and functional principles described above. All of them have the disadvantage of complexity, operational inconvenience and relatively high cost.